Raised floors are commonly employed in facilities such as offices, computer rooms and stock exchanges. A typical raised floor system consists of a series of floor panels supported at a predetermined height above the subfloor by vertical pedestals. The raised floor serves as the working floor for the facility. The space between the raised floor and the subfloor is used to accommodate the electric cables; fiber optic lines; pipes; heating, ventilating and air conditioning (HVAC); and other utility services for the facility. Openings are formed in the raised floor to access the various services at desired locations. Organizing the utility services in predetermined routes below the raised floor is advantageous because it provides a clean and uncluttered working space on the raised floor.
Early raised floor systems relied upon the installer to decide how and where to locate the cables, pipes, and similar routing structures for the various utility services. Often the installer chose to place all of the services on the subfloor, without isolating the services from one another. Such installations were problematic for a variety of reasons. One major problem was the potential exposure of electric cables to moisture due to leaks in the subfloor or pipes, and the pooling of water on the subfloor.
In recognition of the problems associated with these early raise floors systems, a variety of designs have been developed in which the utility services are physically separated from each other. In fact, many installations are now subject to building codes mandating physical separation of the various utility services.
One such conventional system is illustrated in U.S. Pat. No. Re. 33,220 ("the Collier '220 patent"), entitled "Modular Combination Floor Support and Electrical Isolation System for Use in Building Structures." The Collier '220 patent discloses a floor structure support system consisting of a raised floor and one or more additional floors disposed beneath the raised floor. The additional floors support and mechanically isolate the cables and other electrical conductors. Side walls can be installed between the floors to define vertical passages to the main working floor. In addition, one of the floors in the Collier '220 patent can be utilized as an HVAC plenum to route conditioned air throughout the facility.
One major drawback of the Collier '220 patent is the difficulty in relocating equipment on the main floor. The Collier system typically requires the installation of new side walls to create a vertical passage to route the electrical cable and other services to the equipment. In addition, since each level of the Collier '220 patent is coextensive with the raised working floor, the cables and other electrical conductors are not disposed in discrete horizontal pathways, but instead can be haphazardly placed or strewn about each level. This type of cable mismanagement makes relocation of equipment inefficient and time consuming, and is potentially hazardous because of the accumulation of disorganized cables on each level.
Another conventional type of system provides a network of troughs for the electric, fiber optic and other cables. An example of a conventional trough system is illustrated in U.S. Pat. No. 4,596,095, entitled "Underfloor Cable Tray Assembly." A major drawback of conventional trough systems is the use of solid sections of trough. These inflexible systems must therefore typically be designed and manufactured for a single installation at a particular location. Once these systems are installed, it is difficult to extend new sections of trough to route utility services to other locations on the raised floor. Extending a trough section perpendicularly from an existing trough can only be accomplished by cutting a hole in the existing straight trough section or replacing the straight trough section with a "T" section and several shorter straight sections. This is a very expensive and time-consuming process, especially in an a existing installation in an occupied facility.
The troughs in conventional systems are often secured directly to the sub-floor, thereby creating an inflexible, semi-permanent installation. Besides being inflexible, locating the troughs near the subfloor presents several drawbacks. First, locating the troughs on or near the subfloor leaves little room for routing water pipes and other services. Second, installation of new cables is inconvenient because the troughs are located a significant distance below the raised floor. Finally, locating the troughs near the subfloor is problematic because the cables can be exposed to moisture if there is water leakage and pooling.
In some areas, building codes require that all under-floor wiring be completely enclosed in a protective wireway or closed trough. Conventional trough systems address these requirements by providing removable covers that are bolted or otherwise secured to the wiring troughs. Cables that exit through the troughs up to the raised floor are enclosed in vertical troughs or "chimneys" which extend between the trough cover and the raised floor. Relocation of the vertical troughs and removal and reinstallation of the trough covers are time-consuming and inconvenient processes. As a result, the covers are often not installed, even though this may violate the local building codes. If the covers are not installed, users often overfill the troughs and drape cables on top of and over the trough edges. This type of cable mismanagement makes maintenance and equipment relocation inefficient and is potentially dangerous. Moreover, in systems where the space between the raised floor and subfloor serves as an air plenum, a failure to install the covers leaves the cables unprotected and allows plenum air to blow freely around the electrical cables, thereby creating fire safety concerns.
It is therefore an object of the present invention to provide a raised floor cable trough system which is flexible and easy to modify in comparison to conventional systems.
Another object of the present invention is to provide a raised floor cable trough system which reduces the potential for damage due to water leakage and pooling on the sub-floor.
A further object of the present invention to provide a raised floor cable trough system which reduces the likelihood that the wiring troughs will be overfilled.
Another object of the present invention is to provide a raised floor cable trough system which eliminates the need for trough covers and vertical chimneys.
Still another object of the present invention is to provide a raised floor cable trough system which can be readily retrofitted in an existing raised floor installation.
A further object of the present invention to provide a raised floor cable trough system which eliminates the need for drilling and anchoring into the sub-floor.
Still a further object of the present invention is to provide a raised floor cable trough system in which overfilling of the cable troughs can be detected without removing the floor panels.
An advantage of the present invention is to provide a raised floor cable trough system in which the raised floor panels serve as covers for the wiring troughs.
Another advantage of the present invention to provide a raised floor cable trough system in which the side walls of the wiring troughs include regularly space apertures having removable cover plates for permitting easy installation of perpendicular sections of troughs.
Other objects and advantages of the invention will become apparent upon reading the following detailed description and appended claims, and upon reference to the accompanying drawings.